1. Technical Field
The present invention relates to a control system for controlling power transmission from a starter motor to an internal combustion engine for a vehicle, such as an automobile, and power transmission from the internal combustion engine to an accessory.
2. Description of the Related Art
A technique for temporarily stopping an internal combustion engine when a vehicle provided with the internal combustion engine is stopped, for example, to wait for the traffic lights to change has been practiced to reduce the fuel consumption of the internal combustion engine. Generally, an accessory, such as an air conditioner, stops when the internal combustion engine is stopped and, consequently, a heated atmosphere in the passenger compartment makes the passenger compartment uncomfortable.
Techniques for driving accessories by a motor when the internal combustion engine is stopped have been proposed. A technique proposed to prevent useless power consumption in JP-A No. 230012/1999 drives a motor for rotation in the normal direction to start a stopping internal combustion engine and disconnects the motor from an accessory to stop transmitting torque to the accessory, and drives the motor for rotation in the reverse direction to drive the accessory while the internal combustion engine is stopped and disconnects the motor from the internal combustion engine to stop transmitting torque from the motor to the internal combustion engine.
The prior art, however, does not use the motor both as a driving device and a generator, and does not use the motor for power regeneration.
It would be wiser for the automobile that operates the air conditioner while the internal combustion engine is stopped temporarily to regenerate energy that can be recovered because the power consumption of the air conditioner is large.
In a hybrid car provided with both an internal combustion engine and an electric motor as driving means, energy regeneration while the car is decelerated is indispensable in view of energy efficiency.